<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      const str1 = 'hell " o1 '; //单引号中输出双引号
      const str2 = "hell ' o2"; // 双引号中输出单引号
      const str3 = `hell ' " o3`;

      console.log(str1);
      console.log(str2);
      console.log(str3);

      // const num1 = "10";
      // const num2 = 20;
      // const num3 = 30;
    </script>
  </body>
</html>
